Optimization Study of Fluffy Materials Flocking Drainage Pipes to Resist Blockage Based on MD Binding Energy

Shiyang Liu,Feng Gao,Yuanfu Zhou,Xuefu Zhang

doi:10.3390/coatings11070853

Abstract

Drainage pipe blockage resulting from crystals is one of the causes for cracking and leakage of tunnel lining. Therefore, effective prevention from drainage pipe blockage caused by crystals is crucial to ensure the safety and stability of lining structures during the operation of tunnel drainage system. Based on a large number of indoor model tests and numerical simulation analyses, binding energy between four materials and the calcium carbonate aqueous solution (“solid + liquid” system) and that between the four materials and the two typical growth crystals of calcium carbonate (“solid + solid” system) were studied. The research results indicated that: (1) The four materials all had an adsorption effect on the calcium carbonate aqueous solution system, and the PA6 had the greatest adsorption effect while the PP had the smallest adsorption effect; (2) There was spontaneous adsorption between the PVC or PA6 and the two typical growth crystals of calcium carbonate and no adsorption between the PP or SiC and the two typical growth crystals of calcium carbonate unless external energy was in place; (3) The PP and SiC can be used as the materials for drainage pipe flocking, but it shall be ensured that the fluffy material has a good geometrical property. The prevention technology for crystallization that causes drainage pipe blockage fills the gap in the research of drainage pipe blockage caused by crystals, which can reduce the maintenance cost for the operation of the tunnel drainage system and ensure safe and normal operation of the tunnel.

Highlights

With the operation of tunnel projects, tunnel defects gradually emerge, among which drainage pipe blockage caused by crystals is a major factor affecting the service life of a tunnel
Improper treatment of the crystals can affect the smooth operation of a tunnel drainage system and further lead to the cracking and leakage of the tunnel lining (Figure 2)
The attachment of calcium carbonate crystals can be reduced through hydrophobic treatment on concrete base surfaces and PVC pipe walls with protective coating [5,6]; generation of crystals can be effectively lowered by optimizing the concrete materials and the concrete composition ratio, reducing the contact between groundwater and concrete, preventing CO2 from entering the tunnel the contact between groundwater and concrete, preventing CO22 from entering th drainage pipe, as well as adding appropriate fly ash to shotcrete [2,4]

Summary

Introduction

With the operation of tunnel projects, tunnel defects gradually emerge, among which drainage pipe blockage caused by crystals is a major factor affecting the service life of a tunnel. Carbonates formed by the inter-reaction of various ions of groundwater calcify into crystals over time, and these crystals accumulate in drainage pipes and cause blockage (Figure 1). Improper treatment of the crystals can affect the smooth operation of a tunnel drainage system and further lead to the cracking and leakage of the tunnel lining (Figure 2). Even worse, it may affect traffic safety and cause imponderable losses. TechnForFloormgoymthoeftahdberoavainebaaognveaelpyiaspinse,abwllyeosccikasna,gsweeeceathcuaastenadtsbpeyreecstrehynast,ttamalsatnapryerreaessteeaanrmtc,hamecsroaonnleytvherele,psareneavdertnchthieoernes on the atrieonfewtecrehsneaorlcohgeys aot fa dmriacirnoalegveelp. iTpheerbelfoorcek, abgaesedcaounstehde babyovceryinsdtaolosr amroedaetl taesmts acro le atnhderneuamreerifceawl srimesuelaatricohneasnaaltyasems, ibcirnodilnegveeln.eTrghyebreetfworeee,nbtahseemdaotenritahlseaanbdocvryesitnaldsoor mo and numerical simulation analyses, binding energy between the materials and was analyzed by the molecular dynamics software to find the best flocking mate drainage pipes to resist blockage, which can provide a theoretical basis for the me Coatings 2021, 11, 853 was analyzed by the molecular dynamics software to find the best flocking materials for drainage pipes to resist blockage, which can provide a theoretical basis for the mechanism of resisting blockage by drainage pipe flocking

Molecular Dynamics Software

Model Building